romenskiy2012/curl
1
0
Fork 0
mirror of https://github.com/curl/curl.git synced 2026-07-31 03:48:05 +03:00
Code Issues Projects Releases Packages Wiki Activity
curl/CMake/PickyWarnings.cmake
Viktor Szakats f4e23950c7
build: enable -Wcast-qual, fix or silence compiler warnings 
The issues found fell into these categories, with the applied fixes:

- const was accidentally stripped.
  Adjust code to not cast or cast with const.

- const/volatile missing from arguments, local variables.
  Constify arguments or variables, adjust/delete casts. Small code
  changes in a few places.

- const must be stripped because an API dependency requires it.
  Strip `const` with `CURL_UNCONST()` macro to silence the warning out
  of our control. These happen at API boundaries. Sometimes they depend
  on dependency version, which this patch handles as necessary. Also
  enable const support for the zlib API, using `ZLIB_CONST`. Supported
  by zlib 1.2.5.2 and newer.

- const must be stripped because a curl API requires it.
  Strip `const` with `CURL_UNCONST()` macro to silence the warning out
  of our immediate control. For example we promise to send a non-const
  argument to a callback, though the data is const internally.

- other cases where we may avoid const stripping by code changes.
  Also silenced with `CURL_UNCONST()`.

- there are 3 places where `CURL_UNCONST()` is cast again to const.
  To silence this type of warning:
  ```
  lib/vquic/curl_osslq.c:1015:29: error: to be safe all intermediate
    pointers in cast from 'unsigned char **' to 'const unsigned char **'
    must be 'const' qualified [-Werror=cast-qual]
  lib/cf-socket.c:734:32: error: to be safe all intermediate pointers in
    cast from 'char **' to 'const char **' must be 'const' qualified
    [-Werror=cast-qual]
  ```
  There may be a better solution, but I couldn't find it.

These cases are handled in separate subcommits, but without further
markup.

If you see a `-Wcast-qual` warning in curl, we appreciate your report
about it.

Closes #16142
2025-03-10 22:30:15 +01:00

300 lines
14 KiB
CMake
Raw Blame History

#***************************************************************************
# _ _ ____ _
# Project ___| | | | _ \| |
# / __| | | | |_) | |
# | (__| |_| | _ <| |___
# \___|\___/|_| \_\_____|
#
# Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at https://curl.se/docs/copyright.html.
#
# You may opt to use, copy, modify, merge, publish, distribute and/or sell
# copies of the Software, and permit persons to whom the Software is
# furnished to do so, under the terms of the COPYING file.
#
# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
# KIND, either express or implied.
#
# SPDX-License-Identifier: curl
#
###########################################################################
include(CheckCCompilerFlag)
set(_picky "")
if(CURL_WERROR AND
((CMAKE_COMPILER_IS_GNUCC AND
NOT DOS AND # Watt-32 headers use the '#include_next' GCC extension
NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0 AND
NOT CMAKE_VERSION VERSION_LESS 3.23.0) OR # to avoid check_symbol_exists() conflicting with GCC -pedantic-errors
CMAKE_C_COMPILER_ID MATCHES "Clang"))
list(APPEND _picky "-pedantic-errors")
endif()
if(APPLE AND
(CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.6) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.3))
list(APPEND _picky "-Werror=partial-availability") # clang 3.6 appleclang 6.3
endif()
if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
list(APPEND _picky "-Werror-implicit-function-declaration") # clang 1.0 gcc 2.95
endif()
if(MSVC)
if(CMAKE_C_FLAGS MATCHES "[/-]W[0-4]")
string(REGEX REPLACE "[/-]W[0-4]" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
endif()
list(APPEND _picky "-W4")
elseif(BORLAND)
list(APPEND _picky "-w-") # Disable warnings on Borland to avoid changing 3rd party code.
endif()
if(PICKY_COMPILER)
if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang")
# https://clang.llvm.org/docs/DiagnosticsReference.html
# https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
# _picky_enable = Options we want to enable as-is.
# _picky_detect = Options we want to test first and enable if available.
# Prefer the -Wextra alias with clang.
if(CMAKE_C_COMPILER_ID MATCHES "Clang")
set(_picky_enable "-Wextra")
else()
set(_picky_enable "-W")
endif()
list(APPEND _picky_enable
-Wall -pedantic
)
# ----------------------------------
# Add new options here, if in doubt:
# ----------------------------------
set(_picky_detect
)
# Assume these options always exist with both clang and gcc.
# Require clang 3.0 / gcc 2.95 or later.
list(APPEND _picky_enable
-Wbad-function-cast # clang 2.7 gcc 2.95
-Wconversion # clang 2.7 gcc 2.95
-Wmissing-declarations # clang 1.0 gcc 2.7
-Wmissing-prototypes # clang 1.0 gcc 1.0
-Wnested-externs # clang 1.0 gcc 2.7
-Wno-long-long # clang 1.0 gcc 2.95
-Wno-multichar # clang 1.0 gcc 2.95
-Wpointer-arith # clang 1.0 gcc 1.4
-Wshadow # clang 1.0 gcc 2.95
-Wsign-compare # clang 1.0 gcc 2.95
-Wundef # clang 1.0 gcc 2.95
-Wunused # clang 1.1 gcc 2.95
-Wwrite-strings # clang 1.0 gcc 1.4
)
# Always enable with clang, version dependent with gcc
set(_picky_common_old
-Waddress # clang 2.7 gcc 4.3
-Wattributes # clang 2.7 gcc 4.1
-Wcast-align # clang 1.0 gcc 4.2
-Wcast-qual # clang 3.0 gcc 3.4.6
-Wdeclaration-after-statement # clang 1.0 gcc 3.4
-Wdiv-by-zero # clang 2.7 gcc 4.1
-Wempty-body # clang 2.7 gcc 4.3
-Wendif-labels # clang 1.0 gcc 3.3
-Wfloat-equal # clang 1.0 gcc 2.96 (3.0)
-Wformat-security # clang 2.7 gcc 4.1
-Wignored-qualifiers # clang 2.8 gcc 4.3
-Wmissing-field-initializers # clang 2.7 gcc 4.1
-Wmissing-noreturn # clang 2.7 gcc 4.1
-Wno-format-nonliteral # clang 1.0 gcc 2.96 (3.0)
-Wno-sign-conversion # clang 2.9 gcc 4.3
-Wno-system-headers # clang 1.0 gcc 3.0
# -Wpadded # clang 2.9 gcc 4.1 # Not used: We cannot change public structs
-Wold-style-definition # clang 2.7 gcc 3.4
-Wredundant-decls # clang 2.7 gcc 4.1
-Wstrict-prototypes # clang 1.0 gcc 3.3
# -Wswitch-enum # clang 2.7 gcc 4.1 # Not used: It basically disallows default case
-Wtype-limits # clang 2.7 gcc 4.3
-Wunreachable-code # clang 2.7 gcc 4.1
# -Wunused-macros # clang 2.7 gcc 4.1 # Not practical
# -Wno-error=unused-macros # clang 2.7 gcc 4.1
-Wunused-parameter # clang 2.7 gcc 4.1
-Wvla # clang 2.8 gcc 4.3
)
if(CMAKE_C_COMPILER_ID MATCHES "Clang")
list(APPEND _picky_enable
${_picky_common_old}
-Wshift-sign-overflow # clang 2.9
-Wshorten-64-to-32 # clang 1.0
-Wformat=2 # clang 3.0 gcc 4.8
)
if(NOT MSVC)
list(APPEND _picky_enable
-Wlanguage-extension-token # clang 3.0
)
endif()
# Enable based on compiler version
if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.6) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.3))
list(APPEND _picky_enable
-Wdouble-promotion # clang 3.6 gcc 4.6 appleclang 6.3
-Wenum-conversion # clang 3.2 gcc 10.0 appleclang 4.6 g++ 11.0
-Wheader-guard # clang 3.4 appleclang 5.1
-Wpragmas # clang 3.5 gcc 4.1 appleclang 6.0
-Wsometimes-uninitialized # clang 3.2 appleclang 4.6
# -Wunreachable-code-break # clang 3.5 appleclang 6.0 # Not used: Silent in "unity" builds
-Wunused-const-variable # clang 3.4 gcc 6.0 appleclang 5.1
)
endif()
if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 3.9) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 8.3))
list(APPEND _picky_enable
-Wcomma # clang 3.9 appleclang 8.3
-Wmissing-variable-declarations # clang 3.2 appleclang 4.6
)
endif()
if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.3))
list(APPEND _picky_enable
-Wassign-enum # clang 7.0 appleclang 10.3
-Wextra-semi-stmt # clang 7.0 appleclang 10.3
)
endif()
if((CMAKE_C_COMPILER_ID STREQUAL "Clang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.0) OR
(CMAKE_C_COMPILER_ID STREQUAL "AppleClang" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 12.4))
list(APPEND _picky_enable
-Wimplicit-fallthrough # clang 4.0 gcc 7.0 appleclang 12.4 # We do silencing for clang 10.0 and above only
)
endif()
else() # gcc
# Enable based on compiler version
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.3)
list(APPEND _picky_enable
${_picky_common_old}
-Wclobbered # gcc 4.3
-Wmissing-parameter-type # gcc 4.3
-Wold-style-declaration # gcc 4.3
-Wpragmas # clang 3.5 gcc 4.1 appleclang 6.0
-Wstrict-aliasing=3 # gcc 4.0
-ftree-vrp # gcc 4.3 (required for -Warray-bounds, included in -Wall)
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5)
list(APPEND _picky_enable
-Wjump-misses-init # gcc 4.5
)
if(MINGW)
list(APPEND _picky_enable
-Wno-pedantic-ms-format # gcc 4.5 (MinGW-only)
)
endif()
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.8)
list(APPEND _picky_enable
-Wdouble-promotion # clang 3.6 gcc 4.6 appleclang 6.3
-Wformat=2 # clang 3.0 gcc 4.8
-Wtrampolines # gcc 4.6
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.0)
list(APPEND _picky_enable
-Warray-bounds=2 # clang 3.0 gcc 5.0 (clang default: -Warray-bounds)
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 6.0)
list(APPEND _picky_enable
-Wduplicated-cond # gcc 6.0
-Wnull-dereference # clang 3.0 gcc 6.0 (clang default)
-fdelete-null-pointer-checks
-Wshift-negative-value # clang 3.7 gcc 6.0 (clang default)
-Wshift-overflow=2 # clang 3.0 gcc 6.0 (clang default: -Wshift-overflow)
-Wunused-const-variable # clang 3.4 gcc 6.0 appleclang 5.1
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 7.0)
list(APPEND _picky_enable
-Walloc-zero # gcc 7.0
-Wduplicated-branches # gcc 7.0
-Wformat-truncation=2 # gcc 7.0
-Wimplicit-fallthrough # clang 4.0 gcc 7.0
-Wrestrict # gcc 7.0
)
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 10.0)
list(APPEND _picky_enable
-Warith-conversion # gcc 10.0
-Wenum-conversion # clang 3.2 gcc 10.0 appleclang 4.6 g++ 11.0
)
endif()
endif()
#
foreach(_ccopt IN LISTS _picky_enable)
list(APPEND _picky "${_ccopt}")
endforeach()
foreach(_ccopt IN LISTS _picky_detect)
# Use a unique variable name 1. for meaningful log output 2. to have a fresh, undefined variable for each detection
string(MAKE_C_IDENTIFIER "OPT${_ccopt}" _optvarname)
# GCC only warns about unknown -Wno- options if there are also other diagnostic messages,
# so test for the positive form instead
string(REPLACE "-Wno-" "-W" _ccopt_on "${_ccopt}")
check_c_compiler_flag(${_ccopt_on} ${_optvarname})
if(${_optvarname})
list(APPEND _picky "${_ccopt}")
endif()
endforeach()
if(CMAKE_COMPILER_IS_GNUCC)
if(CMAKE_C_COMPILER_VERSION VERSION_LESS 4.5)
# Avoid false positives
list(APPEND _picky "-Wno-shadow")
list(APPEND _picky "-Wno-unreachable-code")
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.2 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.6)
# GCC <4.6 do not support #pragma to suppress warnings locally. Disable them globally instead.
list(APPEND _picky "-Wno-overlength-strings")
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.0 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.7)
list(APPEND _picky "-Wno-missing-field-initializers") # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36750
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 4.3 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 4.8)
list(APPEND _picky "-Wno-type-limits") # Avoid false positives
endif()
if(NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 5.1 AND CMAKE_C_COMPILER_VERSION VERSION_LESS 5.5)
list(APPEND _picky "-Wno-conversion") # Avoid false positives
endif()
endif()
endif()
endif()
# clang-cl
if(CMAKE_C_COMPILER_ID STREQUAL "Clang" AND MSVC)
list(APPEND _picky "-Wno-language-extension-token") # Allow __int64
set(_picky_tmp "")
foreach(_ccopt IN LISTS _picky)
# Prefix -Wall, otherwise clang-cl interprets it as an MSVC option and translates it to -Weverything
if(_ccopt MATCHES "^-W" AND NOT _ccopt STREQUAL "-Wall")
list(APPEND _picky_tmp ${_ccopt})
else()
list(APPEND _picky_tmp "-clang:${_ccopt}")
endif()
endforeach()
set(_picky ${_picky_tmp})
endif()
if(_picky)
string(REPLACE ";" " " _picky "${_picky}")
string(APPEND CMAKE_C_FLAGS " ${_picky}")
message(STATUS "Picky compiler options: ${_picky}")
endif()
Reference in a new issue View git blame Copy permalink